title: Extreme rainfall, vulnerability and risk: a continental-scale assessment for South America.
abstract: Extreme weather continues to preoccupy society as a formidable public safety concern bearing huge economic costs. While attention has focused on global climate change and how it could intensify key elements of the water cycle such as precipitation and river discharge, it is the conjunction of geophysical and socioeconomic forces that shapes human sensitivity and risks to weather extremes. We demonstrate here the use of high-resolution geophysical and population datasets together with documentary reports of rainfall-induced damage across South America over a multi-decadal, retrospective time domain (1960-2000). We define and map extreme precipitation hazard, exposure, affectedpopulations, vulnerability and risk, and use these variables to analyse the impact of floods as a water security issue. Geospatial experiments uncover major sources of risk from natural climate variability and population growth, with change in climate extremes bearing a minor role. While rural populations display greatest relative sensitivity to extreme rainfall, urban settings show the highest rates of increasing risk. In the coming decades, rapid urbanization will make South American cities the focal point of future climate threats but also an opportunity for reducing vulnerability, protecting lives and sustaining economic development through both traditional and ecosystem-based disaster risk management systems.
authors.affiliation: CUNY Environmental CrossRoads Initiative, City College of New York, , New York, NY, USA.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Vörösmarty
authors.forename: Lelys
authors.initials: L
authors.lastname: Bravo de Guenni
authors.forename: Wilfred M
authors.initials: WM
authors.lastname: Wollheim
authors.forename: Brian
authors.initials: B
authors.lastname: Pellerin
authors.forename: David
authors.initials: D
authors.lastname: Bjerklie
authors.forename: Manoel
authors.initials: M
authors.lastname: Cardoso
authors.forename: Cassiano
authors.initials: C
authors.lastname: D'Almeida
authors.forename: Pamela
authors.initials: P
authors.lastname: Green
authors.forename: Lilybeth
authors.initials: L
authors.lastname: Colon
keywords: climate change; extreme weather; flooding; risk; vulnerability; water security